From page 288 of "The World Atlas of Wine", 5th Edition, by Hugh Johnson and Jancis Robinson (the latter being editor of the source you cite):
"The entire Rheingau region was given the Bereich name of Johannisberg, its most famous parish, in 1971."
I'll be the first to admit that I don't understand all of this, so I'll leave it to other contributors here to attempt to make some sense of it. I know when I'm out of my league.
BUT! Nothing that has been said detracts from my original point that naming a wine that is made in the US from grapes grown in the US after some feature of Europe, whether it be a region, a town, a river, or whatever, makes any sense now, except maybe to some Marketing types. The same comment I made with regard to Johannisberg Riesling could have been made with regard to Burgundy, Chianti, etc., etc.
Another hint, if you expect to be taken seriously here. Don't word any more headers the way you worded this one.
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